Bone biomarkers included formation, resorption and regulator are released during the bone remodeling processes. These bone biomarkers have attracted much attention in the clinical assessment of ...osteoporosis treatment in the past decade. Combination with the measurement of bone mineral density, the clinical applications of bone biomarkers have provided comprehensive information for diagnosis of osteoporosis. However, the analytical approaches of the bone biomarkers are still the challenge for further clinical trials. In this mini-review, we have introduced the functions of bone biomarkers and then recently developed techniques for bone biomarker measurements have been systematically integrated to discuss the possibility for osteoporosis assessment in the early stage.
A large number of highly active Ru‐based electrocatalysts have been reported for the hydrogen evolution reaction (HER). The utilization of synergistic effects for promoting HER performance remains ...inadequate, especially for corresponding potential‐driven reactive sites at the atomic level. Herein, a Co‐substituted RuRu2P structure is employed as a model system to reveal the synergistic effect on Ru‐based electrocatalysts and to realize the potential‐driven reactive sites during the HER. Optimized RuRu2P @ Co0.6 exhibits a superior catalytic performance in alkaline electrolytes, achieving a low overpotential of 9 mV at a current density of 10 mA cm–2. To precisely describe the geometrical nature of surface moiety of Co(µ‐O)2Ru, an indicator (β) is established to quantify the strain of Co(µ‐O)2Ru moieties through calculating the LCoL (L = P or O) angles through employing in situ X‐ray absorption spectroscopy. Both bond strain and corresponding metal‐metal distance of CoRu in Co(µ‐O)2Ru moiety can significantly affect the structural tolerance and facilitate the coupling of adsorbed hydrogen atoms during HER. It is believed that the perspective raised in the present work will provide a new avenue to the design of highly active HER catalysts at the atomic scale.
An indicator (β) is established to quantify the strain of Co(μ‐O)2Ru moieties by calculating the LCoL (L = P or O) angles by employing in situ X‐ray absorption spectroscopy. The bond strain of CoRu in Co(μ‐O)2Ru moiety can significantly affect the structural tolerance and facilitate the coupling of adsorbed hydrogen atoms during the hydrogen evolution reaction.
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Metal chalcogenides have been intensively investigated as antibacterial agents due to their unique structures and superior photoactivities. Herein, various structures of copper ...sulfide (CuS), a metal chalcogenide, such as microspheres (MSs), nanosheets (NSs), and nanoparticles (NPs), were developed in this work for antibacterial applications. A hydrothermal process was utilized to synthesize CuS MSs, CuS NSs, and CuS NPs. Under simulated solar light and near-infrared (NIR) light irradiation, the antibacterial behaviors, reactive oxygen species (ROS) production, and light-driven antibacterial mechanisms of CuS MSs, CuS NSs, and CuS NPs were demonstrated with the bacterium Escherichia coli (E. coli). Bacterial growth curves and ROS generation tests indicated that CuS NSs and CuS NPs had higher light-driven antibacterial activities than that of CuS MSs. ROS of hydroxyl (·OH) and superoxide anion radicals (O2−) were investigated via an electron spin resonance (ESR) spectroscopic analysis by respectively incubating CuS MSs, CuS NSs, and CuS NPs with E. coli under simulated solar light irradiation. Furthermore, E. coli incubated with CuS NPs and CuS NSs showed substantial bacterial degradation after NIR laser irradiation, which was attributed to their photothermal killing effects. Light-driven antibacterial mechanisms of CuS NSs and CuS NPs were investigated, and we discovered that under simulated solar and NIR light irradiation, CuS NSs and CuS NPs produced photoinduced electrons, and the copper ions and photoinduced electrons then reacted with atmospheric moisture to produce hydroxide and superoxide anion radicals and heat, resulting in bacterial mortality.
Bacterial infections have caused serious threats to public health due to the antimicrobial resistance in bacteria. Recently, gold nanoclusters (AuNCs) have been extensively investigated for ...biomedical applications because of their superior structural and optical properties. Great efforts have demonstrated that AuNCs conjugated with various surface ligands are promising antimicrobial agents owing to their high biocompatibility, polyvalent effect, easy modification and photothermal stability. In this review, we have highlighted the recent achievements for the utilizations of AuNCs as the antimicrobial agents. We have classified the antimicrobial AuNCs by their surface ligands including small molecules (< 900 Daltons) and macromolecules (> 900 Daltons). Moreover, the antimicrobial activities and mechanisms of AuNCs have been introduced into two main categories of small molecules and macromolecules, respectively. In accordance with the advancements of antimicrobial AuNCs, we further provided conclusions of current challenges and recommendations of future perspectives of antimicrobial AuNCs for fundamental researches and clinical applications.
Single‐atom catalysts (SAs) with the maximum atom utilization and breakthrough activities toward hydrogen evolution reaction (HER) have attracted considerable research interests. Uncovering the ...nature of single‐atom metal centers under operating electrochemical condition is highly significant for improving their catalytic performance, yet is poorly understood in most studies. Herein, Pt single atoms anchoring on the nitrogen–carbon substrate (PtSA/N–C) as a model system are utilized to investigate the dynamic structure of Pt single‐atom centers during the HER process. Via in situ/operando synchrotron X‐ray absorption spectroscopy and X‐ray photoelectron spectroscopy, an intriguing structural reconstruction at atomic level is identified in the PtSA/N–C when it is subjected to the repetitive linear sweep voltammetry and cyclic voltammetry scanning. It demonstrates that the PtN bonding tends to be weakened under cathodic potentials, which induces some Pt single atoms to dynamically aggregate into forming small clusters during the HER reaction. More importantly, experimental evidence and/or indicator is offered to correlate the observed Tafel slope with the dynamic structure of Pt catalysts. This work provides an evident understanding of SAs under electrocatalytic process and offers informative insights into constructing efficient catalysts at atomic level for electrochemical water‐splitting system.
The dynamic reconstruction from the isolated atoms to small clusters on the N‐doped carbon‐supported Pt single‐atom catalyst during the alkaline hydrogen evolution reaction (HER) is clearly revealed by in situ/operando spectroscopic characterizations, based on which a significant correlation between the Tafel slope for HER and the dynamic structure of Pt can be well established.
Gold nanoclusters (AuNCs) have been extensively applied as a fluorescent probe for biomedical applications in imaging, detection, and therapy due to their unique chemical and physical properties. ...Fluorescent probes of AuNCs have exhibited high compatibility, superior photostablility, and excellent water solubility which resulted in remarkable biomedical applications for long-term imaging, high-sensitivity detection, and target-specific treatment. Recently, great efforts have been made in the developments of AuNCs as the fluorescent probes for various biomedical applications. In this review, we have collected fluorescent AuNCs prepared by different ligands, including small molecules, polymers, and biomacromolecules, and highlighted current achievements of AuNCs in biomedical applications for imaging, detection, and therapy. According to these advances, we further provided conclusions of present challenges and future perspectives of AuNCs for fundamental investigations and practical biomedical applications.
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Zeolitic imidazolate framework-67 (ZIF67) derivatives are considered as promising active materials for energy storage owing to the possible formation of cobalt oxide and N-doped ...graphite. Cobalt oxide has multiple redox states for generating redox reactions for charge storage, while N-doped graphite can provide high electrical conductivity for charge transfer. In this study, it is the first time to synthesize binder-free electrodes composed of cobalt oxide and N-doped graphite derived from ZIF67 on carbon cloth (CC) for supercapacitor (SC). Successive oxidation and carbonization along with additional coverage of ZIF67 derivatives are applied to synthesize ZIF67 derivatives composed of cobalt oxide, N-doped graphite and cobalt oxide/N-doped graphite composites with different layer compositions. The highest specific capacitance (CF) of 90.0F/g at 20 mV/s is obtained for the oxidized ZIF67/carbonized ZIF67/carbon cloth (O67/C67/CC) electrode, due to the large surface area and high electrical conductivity benefitted from preferable morphology and growing sequence of Co3O4 and N-doped graphite. The symmetric SC composed of O67/C67/CC electrodes shows the maximum energy density of 2.53 Wh/kg at the power density of 50 W/kg. Cycling stability with CF retention of 70% and Coulombic efficiency of 65% after 6000 times repeatedly charge/discharge process is also obtained for this symmetric SC.
Around the globe, surges of bacterial diseases are causing serious health threats and related concerns. Recently, the metal ion release and photodynamic and photothermal effects of nanomaterials were ...demonstrated to have substantial efficiency in eliminating resistance and surges of bacteria. Nanomaterials with characteristics such as surface plasmonic resonance, photocatalysis, structural complexities, and optical features have been utilized to control metal ion release, generate reactive oxygen species, and produce heat for antibacterial applications. The superior characteristics of nanomaterials present an opportunity to explore and enhance their antibacterial activities leading to clinical applications. In this review, we comprehensively list three different antibacterial mechanisms of metal ion release, photodynamic therapy, and photothermal therapy based on nanomaterials. These three different antibacterial mechanisms are divided into their respective subgroups in accordance with recent achievements, showcasing prospective challenges and opportunities in clinical, environmental, and related fields.
Gold-based plasmonic nanocrystals have been extensively developed for noninvasive photothermal therapy. In this study, gold nanorods (AuNRs) with (200) plane and gold nanobipyramids (AuNBPs) with ...(111) plane were utilized as photothermal agents for noninvasive photothermal therapy. With longitudinal surface plasma bands at ~808 nm, both of AuNRs and AuNBPs revealed photothermal capability and reversibility of laser response under 808-nm near-infrared (NIR) laser irradiation. Moreover, AuNBPs with (111) plane exhibited higher photothermal performance than that of AuNRs with (200) plane under NIR laser irradiation. Density function theory (DFT) simulations revealed that water adsorption energy followed the order Au(111) < Au(100), indicating that the water was easily desorbed on the Au(111) surface for photothermal heating. For the photothermal therapy against Escherichia coli (E. coli), AuNBPs also exhibited higher efficiency compared to that of AuNRs under NIR laser irradiation. Combination of experimental photothermal therapy and DFT simulations demonstrated that AuNBPs with (111) plane were better photothermal agents than that of AuNRs with (100) plane.
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•Plasmonic AuNRs and AuNBPs were prepared as photothermal agents.•AuNRs exhibited (200) plane and AuNBPs exhibited (111) plane.•AuNBPs with (111) plane were better photothermal agents.•DFT simulations demonstrated that water was easily desorbed from Au(111) surface.
We enclose octahedral silver nanocrystals (Ag NCs) in metal–organic frameworks (MOFs) to make mesoscopic constructs O h -nano-Ag⊂MOF in which the interface between the Ag and the MOF is pristine and ...the MOF is ordered (crystalline) and oriented on the Ag NCs. This is achieved by atomic layer deposition of aluminum oxide on Ag NCs and addition of a tetra-topic porphyrin-based linker, 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoic acid (H4TCPP), to react with alumina and make MOF Al2(OH)2TCPP enclosures around Ag NCs. Alumina thickness is precisely controlled from 0.1 to 3 nm, thus allowing control of the MOF thickness from 10 to 50 nm. Electron microscopy and grazing angle X-ray diffraction confirm the order and orientation of the MOF by virtue of the porphyrin units being perpendicular to the planes of the Ag. We use surface-enhanced Raman spectroscopy to directly track the metalation process on the porphyrin and map the distribution of the metalated and unmetalated linkers on a single-nanoparticle level.
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